Ayrault, a former German teacher and long-time Hollande allyknown for his pragmatic approach, has seen his fortunes rise inrecent weeks over those of Socialist Party leader Martine Aubry,more of an old-school leftist.

Several Socialist party insiders and outside advisers toHollande told Reuters that Ayrault is now favourite for the job.They requested anonymity because the candidate is keen to avoidany suggestion that he is taking victory over conservativePresident Nicolas Sarkozy for granted.

With his understanding of Germany's language and culture,the conciliatory Ayrault could be a bridge-builder with Berlinafter an election campaign that focused on Hollande's demands torenegotiate a German-inspired budget discipline pact for Europe.

Mayor of the western city of Nantes, the reserved Ayraulthas been a special advisor to Hollande's campaign, entrustedwith liaising with other European left parties, particularly theopposition Social Democratic Party (SPD) in Germany.

Behind the scenes, the silver-haired 62-year-old has carriedout sensitive missions. Last year, he met advisers to GermanChancellor Angela Merkel in Berlin in an effort to build tieswith her conservative government.

The result of the first round of French voting was widelyseen as giving Ayrault a boost over Aubry, daughter of formerEuropean Commission President Jacques Delors, in the race forthe premiership.

Communist-backed hard leftist Jean-Luc Melenchon scored morepoorly than predicted, finishing fourth with 11.1 percent,easing the pressure on Hollande to name a prime minister capableof reaching out to the far left.

Socialist insiders say Hollande's achievement in beating theincumbent into second place in round one - the first time inrecent history that a challenger has managed this - strengthenedhis hand to impose his personal choice for premier.

Hollande, who like Ayrault comes from the Socialists'moderate social democrat wing, insists he has not yet decidedbut the definition he gave for the post suggest a preference forthe floor leader.

"The person in question must know the Socialist Party well,its left-wing members of parliament and be on the best of termswith me," Hollande said last week.

The Socialist candidate is determined to involve parliamentmore in euro zone crisis management after strategy under Sarkozywas controlled by a handful of unelected advisers.

He has expressed admiration for the German system, whereparliament plays a bigger role in setting and supervising policyand has criticised the concentration of euro zonedecision-making in the "Merkozy" duo, as Merkel and Sarkozybecame known.

Ayrault would be well placed to liaise with both Berlin andthe National Assembly, where he has held the Socialists togetherin government and opposition as floor leader since 1997.

"WE NEED TO FIND CONSENSUS"

The son of a factory worker, he has sat in parliament since1986 and was initially on the Socialists' left wing beforegradually shifting toward social democracy.

By contrast, Aubry, the mayor of Lille, has not been amember of parliament since 1997, when she became minister oflabour and social affairs, introducing the 35-hour work week.

Hollande's insistence that he wants a prime minister withwhom he has a strong personal relationship also appears tosideline Aubry. The pair have had cool relations since shecriticised his stewardship of the Socialists after she succeededhim as party chief, and they clashed head-on during primarieslast year for the Socialists presidential nomination.

If he gets the job, when a new government is announced inmid-May, one of Ayrault's first tasks would be to help sootherelations with Berlin over Hollande's plan to temper the fiscalcompact signed by 25 EU leaders by adding a growth focus.

"The treaty is incomplete," Ayrault told Reuters in a recentinterview, saying a supplementary growth pact was required. "Weneed to discuss this, to reopen the process. Each side needs totake a step toward the other. We need to find a consensus."

But he emphasised that an Hollande government would stick topromises to balance the budget by the end of its five-year term.

"All public spending will be evaluated to see if it isuseful or not," Ayrault told Reuters.

Ayrault long seemed destined to stay a provincial politicianafter winning the mayoralty of Nantes in 1989. A potential thornin his side is opposition by local residents and ecologists tothe construction of a new airport, which he backs, for theprosperous Western city. Protesters have begun a hunger strike.

Another handicap is his lack of ministerial experience. WithHollande never having served as a minister, he may be tempted toopt for a premier who has served in government.

That would give an advantage to Aubry, or to Michel Sapin,Hollande's economic policy chief and a former finance minister.